Flow control for abrasive media



P 5, 1967 w. J. PHYSIOC m 3,339,880

FLOW CONTROL FOR ABRASIVE MEDIA Filed Jan. 17, 1964 24 INVENTOR Willis I P1931100,

ATTORNEYS United States Patent 3,339,880 FLOW CONTROL FOR ABRASIVE MEDIA Willis J. Physioc III, Boonsboro, Md., assignor to The Panghorn Corporation, Hagerstown, Md., a corporation of Delaware Filed Jan. 17, 1964, Ser. No. 338,361 Claims. (Cl. 251-25) The present invention relates to a flow control assembly useful for controlling the flow of particulate media carried by a gas, such as air, under pressure through a conduit. The invention finds particular utility in the portable, direct pressure hose type of abrasive blast cleaning or peening machines wherein the gas carries fluidized abrasive particles.

In the abrasive cleaning field, particularly the pressure blasting art, the maintenance of a shut 01f or regulatory valving systemis often found to be a source of considerable inconvenience and expense, and very few arrangements have been found which work consistently or Well. Because of the nature of a stream of moving abrasive or blastant particles, the life of the usual regulating valve is generally very short. This is due to the fact that a moving abrasive tends to cut and scour the parts, or that it sifts into and across valve seats and fittings causing added wear.

Various devices and techniques have been employed to lengthen the life and increase the reliability of abrasive regulatory devices. To date, however, the results have not been completely successful.

It is an object of the present invention to provide a new, novel and reliable assembly for supplying and controlling the fiow of a stream of abrasive particles being fed through a supply conduit under pressure.

It is still further an object to provide a reliable assem bly for initiating and terminating the flow -of solid particles moving under pressure in a stream of gas.

Another object is to provide a reliable valve assembly which can be installed in any direct pressure hose blast abrasive line.

It is finally an object to provide a valve assembly for use in a direct pressure line which can be operated manually or mechanically to open or shut oil? the flow.

The above and other objects of this invention will become more apparent from the study of the following detailed description and drawing wherein:

FIG. 1 is a vertical section of the valve structure in closed position.

FIG. 2 is a vertical section of the valve structure in open position.

Referring now to the drawing wherein similar reference characters refer to similar parts, the assembly includes an abrasive-gas supply hose 1, the valve assembly, generally identified as 3, connected to the free end of the hose 1, and a nozzle 5 connected to the valve assembly 3.

Leading into the valve assembly 3 is an air or gas pressure line 12. The pressure in line 12 is greater than that in the abrasive-gas entrance end 13 of valve assembly 3 and the supply hose 1. As indicated in the drawing, these pressures may be 90 p.s.i. and 80 p.s.i. respectively.

A plunger 14, extending into upper housing 15 into which pressure line 12 leads, when actuated manually or mechanically, moves a shiftable valve element 16 containing channel 17 against spring 18 and opens pressure line 12 by moving channel 17 into alignment with pressure line 12. At the same time, channel 17 is moved into alignment with exit line 19 leading off from the opposite side of housing 15. Line 19 is, in turn, connected with a pressure expandible diaphragm on air bag 20 located in housing 21.

Diaphragm 20, when expanded, moves downwardly a shaft on link 22 attached to diaphragm 20 and extending into an expanded chamber 24 of valve assembly 3. The shaft 22 terminates in a ball shaped member 26 and when the shaft 22 is moved to its lowermost position, the ball member 26 blocks off exit 28 of the expanded chamber 24 thereby closing oflf the flow of abrasive to the nozzle 5.

In FIG. 2, when plunger 14 is released, spring 18 forces shiftable valve element 16 in the opposite direction and pressure line 12 is closed since the channel 17 is moved out ofalignrnent with line 12. The pressure in expanded diaphragm 20 is released through orifice 30 located in shiftable valve element 16 which is moved into alignment by the action of spring 18. Orifice 31 located in housing passes the released air or gas into the atmosphere. Diaphragm 20 contracts during the release, drawing back shaft 22 and its ball shaped closing member 26 from the exit end of expanded chamber 24 whereby abrasive flow is again initiated.

For purpose of illustration, the pressures in line 12 and entrance end 13 of the valve assembly 3 are indicated as having a pressure of 90 p.s.i and p.s.i. respectively. It is of course understood that these pressures are for purpose of illustration only and that any pressure is useful provided that the pressure in line 12 is sufliciently greater so that diaphragm 20 will expand. The exact pressure differential depends on the speed with which shutofi is desired, the pressure required to expand diaphragm 20, etc. In the preferred aspect of the invention wherein the valve is used in a direct pressure type abrasive blast cleaning or peening machine, the gas pressures are supplied by air from a suitable source (e.g., a compressor). The air can be supplied from separate sources supplying different pressures. Alternatively, the air pressures may be supplied by a single source equipped with a suitable regulator (e.g., venting means) to create a pressure differential.

For the purpose of illustration, plunger 14 is shown to be actuated manually in the drawing. The operator can simply hold the discharge nozzle 5 in his hand and press plunger 14 when he desires to terminate the abrasive flow. It is, of course, understood that plunger 14 may also be actuated mechanically such as in response to a remote control device in turn actuated manually or by a suitable timing device.

Closing means 26 has been illustrated as a ball fitting tightly into the down stream side or exit 28 of expanded chamber 24. It is contemplated, however, that this closing means can be of any suitable shape so long as it operates to close exit end 28 upon pressure of expanding diaphragm 20.

The actuating valve elements contained in housing 15 can be located any desired distance from pressure line entrance end 13 of valve assembly 3 and the closing ele ments contained in housing 21. Thus connecting line 19 may be of great length allowing the operator to be located a substantial distance from the end of hose 1 and housing 21. Line 19 on the other hand may be relatively short and, in fact, housing 15 may be attached to housing 21 and the entire valve mechanism contained in a single unitary housing.

In FIGS. 1 and 2, spring 18 has been illustrated as forcing the closing of line 12 when pressure is released by plunger 14. It is of course obvious that if one desires to have line 12 closed when pressure is exerted on plunger 14, this can be easily arranged by locating channel 17 in shiftable valve element 16 in alignment with pressure line 12 when spring 18 is not under compression. In this embodiment, spring 18 forces shiftable valve element up and places channel 17 in alignment with pressure line 12. Upon acitvating plunger 14, spring 18 is compressed by the movement of shiftable valve element 16 and channel 17 is moved out of alignment with pressure line 12 and the line is closed. Upon release of pressure from plunger 14, spring 18 again forces shiftable valve element 16 upwards and realigns channel 17 with line 12.

Throughout the foregoing description tension means 18 has been indicated as a spring. It is of course obvious that this may be any means which will move shiftable valve element 16 upon release of pressure from plunger 14. For example, shiftable valve element 16 may be shifted by means of gas pressure, e.g., created by placing a T-joint in line 12 close by housing and supplying pressure to shiftable valve element 16 by means of an additional line connection.

Since it is obvious that many changes and modifications can be made in the above described details without departing from the nature or spirit of the invention, it is to be understood that the invention is not to be limited to said details except as set forth in the appended claims.

What is claimed is:

1. A flow control assembly comprising a free flow conduit for dispensing an abrasive medium under pressure, a valve seat axially disposed in said conduit, a free flow valve chamber communicating with said conduit, a valve seat at the juncture of said conduit and valve chamber, multi-seating shut-off means in said conduit movable between said valve seats, said conduit being axially unobstructed when said shut off means is seated at said juncture to permit the abrasive medium to axially flow directly through said conduit, and pressure responsive means in said valve chamber connected to said shut-off means for seating upon said valve seat in said conduit to terminate flow therethrough when the pressure in said valve chamber is made greater than the pressure in said conduit and for seating upon said juncture valve seat to close off communication between said conduit and valve chamber when the pressure in said valve chamber is made less than the pressure in said conduit.

2. An assembly as set forth in claim 1 wherein said shut-off means is a ball valve, and said pressure responsive means includes an air bag connected to said ball valve by a link extendable through said juncture valve seat.

3. An assembly as set forth in claim 1 including an upper gas passageway, a lower gas passageway communicating with said pressure responsive means, laterally shiftable means being between said passageways, said shiftable means including a gas passage and at least one passageway closing surface, said shiftable means including means for selectively releasing pressurized gas in said lower passageway to the atmosphere, and control means connected to said shiftable means for selectively disposing said gas passage between said upper and lower passageways to open communication between them and for disposing said closing surface against one of the passageways for closing communication between them.

4. An assembly as set forth in claim 3 wherein said shiftable means is mounted in a housing remote from said valve chamber, and resilient means in said housing reacting against shiftable means for urging said shiftable means in a position for closing communication between said passageways.

5. An assembly as set forth in claim 4 wherein said shut-off means is a ball valve, and said pressure responsive means includes an air bag connected to said ball valve by a link extendable through said juncture valve seat.

References Cited UNITED STATES PATENTS 644,473 2/ 1900 Sellers 251-321 826,637 7/1906 Wilkins 25161.1 X 2,445,163 7/ 1948 Williamson 25125 2,676,609 4/1954 Pfarrer 251--25 X 2,704,648 3/1955 Cobb 251-61 2,934,307 4/1960 Henderson 251-330 X 3,085,780 4/1963 Yale 25161 FOREIGN PATENTS 33,886 4/1905 Switzerland.

M. CARY NELSON, Primary Examiner.

ARNOLD ROSENTHAL, Examiner.

E. K. FEIN, Assistant Examiner. 

1. A FLOW CONTROL ASSEMBLY COMPRISING A FREE FLOW CONDUIT FOR DISPENSING AN ABRESIVE MEDIUM UNDER PRESSURE, A VALVE SEAT AXIALLY DISPOSED IN SAID CONDUIT, A FREE FLOW VALVE CHAMBER COMMUNICATING WITH SAID CONDUIT, A VALVE SEAT AT THE JUNCTURE OF SAID CONDUIT AND VALVE CHAMBER, MULTI-SEATING SHUT-OFF MEANS IN SAID CONDUIT MOVABLE BETWEEN SAID VALVE SEATS, SAID CONDUIT BEING AXIALLY UNOBSTRUCTED WHEN SAID SHUT OFF MEANS IS SEATED AT SAID JUNCTURE TO PERMIT THE ABRESIVE MEDIUM TO AXIALLY FLOW DIRECTLY THROUGH SAID CONDUIT, AND PRESSURE RESPONSIVE MEANS IN SAID VALVE CHAMBER CONNECTED TO SAID SHUT-OFF MEANS FOR SEATING UPON SAID VALVE SEAT IN SAID CONDUIT TO TERMINATE FLOW THERETHROUGH WHEN THE PRESSUE IN SAID VALVE CHAMBER IS MADE GREATER THAN THE PRESSURE IN SAID CONDUIT AND FOR SEATING UPON SAID JUNCTION VALVE SEAT TO CLOSE OFF COMMUNICATION BETWEEN SAID CONDUIT AND VALVE CHAMBER WHEN THE PRESSURE IN SAID VALVE CHAMBER IS MADE LESS THAN THE PRESSURE IN SAID CONDUIT. 